Largest Square Submatrix of all 1's NoSIMD_C#

Find the largest square submatrix consisting entirely of 1s as fast as possible.

Input

A 10,000 x 10,000 matrix of uint8 values (0 or 1) on STDIN.

0, 1, 0, 1, 1
0, 1, 1, 1, 1
0, 0, 1, 0, 0
1, 0, 1, 1, 0

Output

Print the side length of the largest all-ones square submatrix to STDOUT. The answer is guaranteed to be greater than 1.

For the example above, the output is:

2
Back to listJun 17, 2026 03:21Victor MerckléVictor MerckléError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jun 17, 2026 03:2208,721,6771,243,00002,113,536expected "53", got "50 "
2Jun 17, 2026 03:2208,487,9161,275,00002,113,536expected "58", got "50 "
3Jun 17, 2026 03:222,3108,381,373924,00002,113,536
4Jun 17, 2026 03:222,9358,474,1591,174,00002,113,536
5Jun 17, 2026 03:223,1208,527,0221,248,00002,113,536
6Jun 17, 2026 03:223,1578,538,3801,263,00002,113,536
7Jun 17, 2026 03:223,2658,637,4911,306,00002,113,536
8Jun 17, 2026 03:223,3328,590,9801,333,00002,113,536
9Jun 17, 2026 03:223,4278,669,6211,371,00002,113,536